Data: COVID-19 was in Michigan during presidential primary campaigns
Lansing — COVID-19 already had infected hundreds of Michiganians as U.S. Sen. Bernie Sanders and former Vice President Joe Biden barnstormed the state in early March seeking the Democratic presidential nomination, according to state health department data.
Infections of the novel coronavirus were surfacing — but not yet confirmed — more than a week before March 10, the date of Michigan's pivotal presidential primary election and when the state officially confirmed the first case here.
Although they tested positive at a later date, at least 365 Michigan residents' symptoms of the virus began before March 10, according to statistics tracked and publicly released by the state Department of Health and Human Services. There can be a lag of up to 14 days before someone who is infected begins feeling symptoms, according to health experts.
According to the state's data, 13 individuals who later tested positive began feeling symptoms on March 1. Of those, nine were from the southeast Michigan counties of Macomb, Monroe, Oakland, St. Clair, Washtenaw and Wayne. The numbers are listed by emergency preparedness regions.
After someone tests positive, a member of the health department reaches out to the person and asks when the person began feeling ill, said Lynn Sutfin, spokeswoman for the health department. That's how the state tracked the "onset" data that's available.
Officials couldn't say last week whether any of those individuals with symptoms in early March attended campaign rallies, voted at precincts or joined other large gatherings, Sutfin said.
But people could have had infections weeks or "perhaps even a month or two" before the first known cases occurred, said Stephen Hawes, an epidemiology professor at the University of Washington.
It is "highly likely that in most communities, the first cases were present before ascertained by hospitals or health departments," Hawes added.
Some epidemiologists already have said Michigan's March 10 presidential primary could have played a role in spreading the virus here. The state ranks above most of its Midwestern neighbors for the number of confirmed COVID-19 cases and fourth nationally for the number of deaths linked to the virus.
Sanders held seven Michigan campaign events in the four days before the primary, with most of them being rallies. Biden held three events on March 9, concluding with a rally at Detroit Renaissance High School attended by Gov. Gretchen Whitmer and Democratic U.S. Sens. Cory Booker of New Jersey and Kamala Harris of California.
Last month, in an interview with The Detroit News, Whitmer said it likely would not do much good to "relitigate every event that occurred in the month or two leading up to our first cases."
"I just acknowledge that we now know that any public gathering is a bad idea," said Whitmer, when asked about the role the primary rallies might have played in accelerating the virus spread in Michigan.
She noted there were other events, besides the rallies, that might have contributed to potential spread, including Big Ten basketball games. And the lack of clear federal guidance at the time meant "people weren't as well informed as we should have been and taking seriously as we should have been," Whitmer said.
When restrictions began
Whitmer banned gatherings of more than 250 people on March 13, three days after the primary election and four days after she attended the rally in Detroit with Biden that drew a crowd of about 2,000 people.
The Detroit rally featured volunteers giving out hand sanitizer as participants headed into Renaissance High School.
A day later, Whitmer held a news conference, confirming the first cases of the virus in Michigan.
"It has moved into Michigan," the governor said. "... Please make sure your family and friends are taking every preventative measure possible."
The tests confirming the initial cases involved an Oakland County woman with a recent history of international travel and a Wayne County man with a recent history of domestic travel.
The Detroit event was the lone large rally that Biden held in Michigan before the primary as he held two smaller, restricted events in Grand Rapids and Flint. But Sanders held a series of large events across the state before the primary.
On March 6, a Sanders rally at the TCF Center in Detroit drew about 6,000 people. On March 7 and March 8, he also held events in Dearborn, Flint and Grand Rapids, culminating with a March 8 rally on the campus of the University of Michigan that drew more than 10,000 people.
But large political events weren't the only major attractions that weekend. On March 7 — three days before Michigan confirmed its first cases — the Utah Jazz played the Detroit Pistons before an announced crowd of more than 16,000 at Little Caesars Arena.
Several players, including Jazz Center Rudy Gobert, who played in that game, later tested positive for COVID-19. Gobert, who was the first known NBA player with the virus, and teammate Donovan Mitchell both stayed at the downtown Westin Book Cadillac hotel, prompting warnings that month from Mayor Mike Duggan.
Whitmer noted she attended the sold-out March 8 senior day basketball game at Michigan State University's Breslin Center and "in retrospect, it was very close in time to when our first cases appeared."
When symptoms flared up
As of March 7, 185 Michigan residents who would later test positive for COVID-19 already had symptoms, according to the state's data. As of March 8 — the day of the 10,000-person rally in Ann Arbor for Sanders — 245 residents who later tested positive for COVID-19 had symptoms.
The state of Michigan found out about the onset of the individuals' symptoms after they tested positive and were contacted, health department spokeswoman Sutfin said.
Asked if any contact tracing had been done to see if the people attended campaign rallies or other large events, Sutfin said the individuals would have been asked what day they fell ill and whom they were in contact with since that point.
If large events were mentioned, the information would be included in state reports, but there isn't an easy way to pull those details out of the reports, she said.
"This is a text field and there is not a way to extract this info without manually going through each and every report, almost 50,000 in all," she said.
Hawes, the University of Washington epidemiology professor, said a primary election has the potential to increase the rate of contact among people.
"I don't know of any research evidence yet to suggest that these events have been impactful, but there are plenty of instances in the media in which gatherings including infected individuals have resulted in transmission/spread of the virus on a large local scale," Hawes said in April.
Like Hawes, Stanford University epidemiologist John Ioannidis also surmised early on that the virus in Michigan was present much earlier than March 10.
"The first positive tests, even though they were announced March 10, it’s clear that people must have been infected much earlier," said Ioannidis, professor of medicine and of epidemiology and population health at Stanford University.
"Original cases could have been early February, if not earlier," he said in a late March interview.
The Detroit Metropolitan Airport also could have contributed to the spread, he said.
The airport was one of 11 nationwide designated in February to continue receiving flights from China amid federal travel restrictions. When restrictions were expanded to other foreign travelers in March, the Detroit airport again was designated as one of 11 airports to continue receiving travelers from those countries.
"You may have had seeding from multiple international destinations converging on Michigan," Ioannidis said.
It's difficult to pinpoint a single event that could have contributed to the spread in any location, he said. But there are theories, Ioannidis said, that a Feb. 19 large soccer match in Bergamo, Italy, accelerated the spread of the virus there.
"Any event that attracted lots of people in close contact is likely to have helped spread the virus as well," Ioannidis said.
After banning large gatherings on March 13, Whitmer issued her first stay-at-home order on March 23, generally prohibiting public gatherings and requiring people to stay in their homes.
Whitmer's latest stay-at-home order is in place through May 28.